IPv6 Adresses does not get renewed after Prefix changes

[DoomSalamander]

I got a really annoying problem when my ISP changes the prefix (I think every 24h) that the LAN doesn't get new IPV6 addresses and the internet is bascially down and I need to manually edit and save a LAN connection to get new addresses. Is this problem known? I connect over PPPoE with a 56 Prefix delagation over DHCPv6 and let the lan track the interface.

[marjohn56]

It's a known issue. Why ISPs do this is beyond me there's no need for it. Of course, if you pay for the business type connection the addresses stay static.


However, we were making progress into a fix for this, it's just not a simple fix. When the address changes dhcp6c should apply the change the LAN interface. If you look at system logs general you should see that so first of all is that happening?

[DoomSalamander]

Thanks for telling me that this is a known issue. I will look into it when it happends again. Currently, I see lots of those:

dhcp6c: dhcp6c RENEW on pppoe0
dhcp6c[76416]: Sending Renew
dhcp6c[76416]: Received REPLY for RENEW

Happends every 15 minutes.

[marjohn56]

Your ISP needs shooting. Doing a lease of 30 minutes on IPv6 is madness. A 30 minute lease will renew at half the interval so 15 minutes.


I though Sky UK were a bit loopy at an hour, but yours takes the biscuit. What you are seeing is quite normal, but when you see a 'Request' statement in the log, apart from first boot, that's what you are looking for. A renew means nothing has changed.

[DoomSalamander]

Your ISP needs shooting. Doing a lease of 30 minutes on IPv6 is madness. A 30 minute lease will renew at half the interval so 15 minutes.

My ISP is Telekom Germany btw. Germany is really behind internet wise... I am also not sure if this 30 minute lease is correct but seems really crazy to me too. I guess nothing that I can really do about. Maybe gonna call them later about that.

[marjohn56]

As as side note, there are a couple of things that try and  mitigate the stupidity of some ISPs, these two things were developed over on the darkside when I used Sky UK as my ISP. Firstly make sure 'Prevent Release' is ticked in the WAN dhcp6 options and secondly, under interfaces > settings is the DHCP Unique Identifier option, click on 'Insert the existing DUID' and then save. It may not fix your problems, only a decent ISP will do that but it may help.

[DoomSalamander]

The problem hasn't been happening since a few days. I honestly don't know what is going on anymore. I did what you suggested and so far has been good.